1. Field of the Invention
The present invention relates to an image sensor camera module, and more particularly, to an image sensor camera module, wherein a focus adjusting process is not performed, and a method of manufacturing the image sensor camera module.
2. Description of the Related Art
Image sensors are semiconductor devices capable of taking photographs of images of human beings or objects. The market of these image sensors has been rapidly expanded as they have been embedded into portable phones as well as digital cameras or camcorders commercially available. Such an image sensor is manufactured in the form of a camera module and mounted into the aforementioned apparatuses.
A camera module generally includes a lens, a holder, an image sensor and a printed circuit board, and is manufactured by a chip on board (COB), chip scale package (CSP) or chip on film (COF) method. In the camera module, the image sensor is electrically connected to the printed circuit board, and the holder is fixed on the printed circuit board. The lens is mounted to a lens barrel and fastened to a lens seating portion provided in the holder. An outer rim of the lens barrel and the lens seating portion are manufactured to have a shape of threads so that the lens barrel is threadedly fastened to the lens seating portion. After the lens barrel is fastened to the lens seating portion, the lens barrel and the holder adhere to each other using an adhesive.
In the conventional camera module, a focus adjusting process should be performed before the lens barrel and the holder are adhered to each other in order to adjust a distance between the lens barrel and the image sensor. Due to the focus adjusting process, an apparatus for focus adjustment is further required and a manufacturing time is increased, whereby an automation process can be hardly achieved.
In addition, during the process of fastening the lens barrel to the holder, particles are produced by the friction between the threads of the holder and the lens barrel. If such particles are introduced to the image sensor, an image defect may be caused in the camera module. Further, tilting of the image sensor and the holder may be caused during the process of manufacturing the camera module, and therefore, homogeneity of the focus quality of the camera module may not be achieved.
Meanwhile, since the conventional camera module should be mounted with a separate IR filter to pass through light having a specific wavelength band, increase of cost and deterioration of optical transmittance are inevitable. Moreover, it is difficult to mount the IR filter particularly when the flange back length (FBL) from the image sensor to the bottom of the lens is configured to be short, which makes it difficult to design a lens having a short FBL.